When using a communications device linked to a vehicle via a connection such as a Bluetooth connection, impaired quality occurs regarding a voice quality of a connection to an external communications device connected to the vehicle, which may be due to settings of the communications device, which are optimized for uncoupled communications.
European document EP 203 18 46 A1 discloses a method for calibrating a hands-free device in a vehicle, in which a test signal to be generated by the hands-free device is compared against a predefined signal.
European document EP 188 32 13 A1 presents a method for calibrating a hands-free device, in which a test signal is alternatingly transmitted between the hands-free device and a terminal, and in which a respective received test signal is used for a comparison against a respective stored test signal.
Document EP 1 583 265 A1 discloses a method for calibrating an arrangement with a transmitter and a receiver, in which the receiver and the transmitter are switched into a test mode wherein signal parameters of a transmission signal are measured and used for calibration purposes.